diff --git a/include/xo/reader/define_xs.hpp b/include/xo/reader/define_xs.hpp
index dc5a5944..5e70012c 100644
--- a/include/xo/reader/define_xs.hpp
+++ b/include/xo/reader/define_xs.hpp
@@ -44,9 +44,9 @@ namespace xo {
 
             bool admits_rightparen() const;
             bool admits_colon() const;
+            bool admits_semicolon() const;
 
             virtual bool admits_symbol() const override;
-            virtual bool admits_semicolon() const override;
             virtual bool admits_singleassign() const override;
 
             // virtual void on_f64(..) override
diff --git a/include/xo/reader/exprstate.hpp b/include/xo/reader/exprstate.hpp
index b6807776..c75870ce 100644
--- a/include/xo/reader/exprstate.hpp
+++ b/include/xo/reader/exprstate.hpp
@@ -74,8 +74,10 @@ namespace xo {
 
             /** true iff this parsing state admits a symbol as next token **/
             virtual bool admits_symbol() const;
+#ifdef OBSOLETE
             /** true iff this parsing state admits a semicolon as next token **/
             virtual bool admits_semicolon() const;
+#endif
             /** true iff this parsing state admits a singleassign '=' as next token **/
             virtual bool admits_singleassign() const;
 
diff --git a/include/xo/reader/paren_xs.hpp b/include/xo/reader/paren_xs.hpp
index 61a057ae..058cdf37 100644
--- a/include/xo/reader/paren_xs.hpp
+++ b/include/xo/reader/paren_xs.hpp
@@ -35,7 +35,6 @@ namespace xo {
             bool admits_rightparen() const;
 
             virtual bool admits_symbol() const override;
-            virtual bool admits_semicolon() const override;
             virtual bool admits_singleassign() const override;
 
             virtual void on_expr(ref::brw<Expression> expr,
diff --git a/include/xo/reader/progress_xs.hpp b/include/xo/reader/progress_xs.hpp
index 47912d20..9ec61099 100644
--- a/include/xo/reader/progress_xs.hpp
+++ b/include/xo/reader/progress_xs.hpp
@@ -25,12 +25,7 @@ namespace xo {
             bool admits_f64() const;
 
             virtual bool admits_symbol() const override;
-            virtual bool admits_semicolon() const override;
             virtual bool admits_singleassign() const override;
-#ifdef OBSOLETE
-            virtual bool admits_leftparen() const override;
-            virtual bool admits_rightparen() const override;
-#endif
 
             virtual void on_expr(ref::brw<Expression> expr,
                                  exprstatestack * p_stack,
diff --git a/src/reader/exprstate.cpp b/src/reader/exprstate.cpp
index 2eaac5bb..3416f7d1 100644
--- a/src/reader/exprstate.cpp
+++ b/src/reader/exprstate.cpp
@@ -76,6 +76,7 @@ namespace xo {
             return false;
         }
 
+#ifdef OBSOLETE
         bool
         exprstate::admits_semicolon() const {
             switch (exs_type_) {
@@ -97,6 +98,7 @@ namespace xo {
 
             return false;
         }
+#endif
 
         bool
         exprstate::admits_singleassign() const {
@@ -202,14 +204,9 @@ namespace xo {
 
             constexpr const char * self_name = "exprstate::on_semicolon";
 
-            if (!this->admits_semicolon())
-            {
-                throw std::runtime_error(tostr(self_name,
-                                               ": unexpected semicolon for parsing state",
-                                               xtag("state", *this)));
-            }
-
-            assert(false);
+            throw std::runtime_error(tostr(self_name,
+                                           ": unexpected semicolon for parsing state",
+                                           xtag("state", *this)));
         }
 
         void
diff --git a/src/reader/paren_xs.cpp b/src/reader/paren_xs.cpp
index 232bdb72..448e0faa 100644
--- a/src/reader/paren_xs.cpp
+++ b/src/reader/paren_xs.cpp
@@ -17,9 +17,6 @@ namespace xo {
         bool
         paren_xs::admits_symbol() const { return true; }
 
-        bool
-        paren_xs::admits_semicolon() const { return false; }
-
         bool
         paren_xs::admits_singleassign() const { return false; }
 
diff --git a/src/reader/progress_xs.cpp b/src/reader/progress_xs.cpp
index 16f31ce2..3a978505 100644
--- a/src/reader/progress_xs.cpp
+++ b/src/reader/progress_xs.cpp
@@ -17,20 +17,14 @@ namespace xo {
         bool
         progress_xs::admits_symbol() const { return false; }
 
+#ifdef OSBOLETE
         bool
         progress_xs::admits_semicolon() const { return true; }
+#endif
 
         bool
         progress_xs::admits_singleassign() const { return false; }
 
-#ifdef OBSOLETE
-        bool
-        progress_xs::admits_rightparen() const {
-            /* satisfies expression form */
-            return true;
-        }
-#endif
-
         bool
         progress_xs::admits_f64() const { return false; }